Tonneau cover apparatus having rear bar lock

ABSTRACT

A tonneau cover apparatus for attaching a flexible cover about a cargo box of a vehicle, preferably a pickup truck. The apparatus preferably includes, a support frame removably attached about the perimeter of a cargo box of the vehicle, an elongated end plate attached to an end of the flexible cover, an end plate engagement member attached to the support frame, preferably one on each side of the support frame, and a locking member movably attached to the end plate. The end plate is preferably attached to an end of the flexible cover and is configured to cooperatively engage and pivot with respect to the end plate engagement member or members into and out of a fixed stretching position wherein the flexible cover can be correspondingly be tensed and relaxed. The end plate may be retained in the fixed stretching position by the locking member, in alternate embodiments, a plurality of locking members are provided, preferably locking members that slide within a channel in the end plate. In preferred embodiments the locking member or members are spring biased toward a locking position where the locking member engages a flange of the support frame to prevent the end plate from moving out of the fixed stretching position.

CROSS-REFERENCE TO OTHER APPLICATIONS

The present application continuation of co-pending U.S. patentapplication Ser. No. 09/930,680 filed Aug. 14, 2001, entitled TONNEAUCOVER END PLATE SECURING MECHANISM HAVING RADIAL ENGAGING SURFACE, whichclaims the benefit of U.S. Provisional Patent Application Ser. No.60/225,109 filed Aug. 14, 2000, entitled TONNEAU COVER HAVING REAR BARLOCK, each of which are incorporated herein by reference and are relatedto U.S. patent application Ser. No. 09/929,991 filed Aug. 14, 2001,entitled TONNEAU COVER HAVING REAR BAR LOCK, now U.S. Pat. No.6,543,835, issued Apr. 8, 2003.

BACKGROUND OF THE INVENTION

The present invention related to tonneau covers having a rear bar or endplate and end plate engagement members cooperating to impart tension toa flexible cover attached to the end plate when the end plate ispositioned in a closed or fixed stretching position, particularly atonneau cover apparatus having an end plate including a locking memberor members slidably engaged within the end plate.

DESCRIPTION OF THE PRIOR ART

Numerous protective covers for preventing rain, debris and wind fromdamaging or disrupting the contents of a pickup truck bed are currentlyavailable. Generally, the covers are made of some sort of fabric, oftencoated with a polymeric material, which is detachably fastenable to arigid frame so as to enclose and protect a given area The coveringmaterials used are generally stretchable to the extent that once theyare in a position, they are pulled taut and then attached to the frameby numerous methods such as snaps, grommets, or hook-and-loop fastenersand stretcher bars.

The use of hook-and-loop type fasteners and stretcher bars to fasten acover to a frame structure forms the subject matter of U.S. Pat. Nos.5,076,338 ('338 patent) and U.S Pat. No. 5,174,353 ('353 patent) issuedto Steven Schmeichel et al., the disclosures of which are incorporatedherein by reference.

In the Schmeichel et al. patents, an edge portion of a covering fabricis attached to a generally L-shaped end plate or stretcher bar. The endplate is provided with a peak or crests, which pivotally contacts endsof the frame structure as the end plate is rotated into a fixedstretching position. As the end plate rotates into the fixed, stretchingposition, an enlarged ridge of the end plate is either captured by aspring loaded lock element as depicted in a first embodiment. After theenlarged ridge passes the lock or pawl element, the lock or pawl elementsprings back to its undeflected state thereby maintaining the end platein the fixed, stretching position. In order to move the end plate out ofthe fixed stretching position, the biasing force of the lock or the pawlelement must be overcome. In th first embodiment, this biasing force maybe overcome by the movement of the enlarged ridge as the end plate ispivoted out of the fixed stretching position. In the second embodiment,deflection of the pawl is best accomplished by manipulating a releasemember which projects from a portion of a latching member, or by openingthe tailgate and manually disengaging the pawl from the enlarged ridge.

Although the Schmeichel et al. patents teach a number of significantimprovements over the prior art, there are several limitations of theprior art, which are addressed and improved upon by the presentinvention.

One limitation of the first embodiment of the Schmeichel et al. patents,as depicted, is that the Lashed lock member, by virtue of it's resilientnature, merely imparts a dynamic force, which tends to maintain the endplate in the fixed stretching position. This force, however, can beovercome by the action of the enlarged ridge as it moves past theinclined portion of the L-shaped lock. Thus, the L-shaped lock does notfunction as a lock in a conventional sense.

A limitation of the second embodiment of the Schmeichel et al. patentsis in the location and construction of the lock element. As depicted,the lock element comprises a pawl element, which is attached to one endof an elongated leaf spring. The other end of the leaf spring isattached to a connector, which in turn is connected to a side rail ofthe support frame structure. While this embodiment functions to lock theend plate and support frame structure in the fixed stretching position,it would appear that absent support, the pawl element may be forciblydisengaged and/or damaged by forcible movement of the end plate out ofthe fixed, stretching position.

Another limitation of the second embodiment of the Schmeichel et al.patents is that the end plate may be disengaged from the lock member bya person with knowledge of the location of the release member.

A limitation common to both the first and second embodiments of theSchmeichel et al. patents regards the attachment point and the design ofthe engagement member (or strike) which engages the end plate. Asdepicted in the drawings the strike is attached to the frame structureby a fastening element located a substantial distance from the inclinedportion of the strike. This allows the strike to be flexed or bentupwardly in reaction to the stress foes exerted on the strike when theend plate is pivoted into and out of the fixed stretching position.Repeated flexure and/or bending may result in loosening and/or prematurefailure of the strike. Additionally, the strike includes a relativelythin lip portion which extends beyond the body of the strike and whichrotatingly contacts the end plate as it is pivoted into and out of thefixed stretching position. This lip portion is subject to high amountsof stress and is subject to flexure and/or bending which may lead topremature failure.

Another limitation common to both the first and second embodiments ofthe Schmeichel et al. patents is in the attachment of the support frameabout the perimeter of a cargo box of the vehicle. In Schmeichel et al.,a support frame is attached to an inner side-wall by a C-shaped clamp.The effectiveness of the clamp may, however, become compromised byovertightening the clamping bolt and may lead to deformation and/orfailure the body of the clamp. Additionally, due to the tapered verticalattachment portion of the frame support, there is a tendency for theclamp to become dislodged from the clamping position.

The present invention provides improvements which address these andother limitations associated with the prior art.

SUMMARY OF THE INVENTION

The present invention relates to a tonneau cover apparatus for attachingand locking a flexible cover about a cargo box of a vehicle such as apickup truck. The apparatus preferably includes a support frame, whichis removably attached about the perimeter of the cargo box of thevehicle by at least one clamp. The flexible cover is attached to thesupport frame and to an end plate. The end plate is configured topivotally engage an end plate engagement member, which is attached tothe support frame. As the end plate pivots about the end plateengagement member to a fixed stretching position, the flexible cover issuitably stretched or tensed. The end plate is preferably releasablyretained in the fixed stretching position by a locking member which isoperatively connected to the end plate. In preferred embodiments, thelocking member is slidably secured to the end plate. The end platepreferably includes two locking members, one at each end of the endplate.

An object of the present invention is to improve the attachment of thesupport frame to an inner sidewall of a vehicle.

Another object of the present invention is to reduce the risk of overtightening in an attachment clamp.

Another object of the present invention is to maximize and simplifysecurement of the end plate engagement member to the support frame.

Yet another object of the present invention is to reduce areas of highstress concentrations in the end plate engagement member.

Still another object of the present invention is to lessen the exposureof the latching member relative to the support frame.

Another object of the present invention is to minimize deflection of theengagement portion of the latching member in response to force exertedby the end plate.

Yet another object of the present invention is to provide a superiorside ba securing clamp which withstands the normal stresses associatedwith securing the support frame to side walls of the pickup truck.

Still another object of the present invention is to reduce inadvertentand/or unauthorized disengagement of a flexible cover from a cargo boxof a vehicle.

These and various other advantages and features of novelty whichcharacterize the present invention are pointed out with particularity inthe claims annexed hereto and forming a part hereof However, for abetter understanding of the invention, its advantages and objectsobtained by its use, reference should be made to the drawings which forma flier part hereof, and to the accompanying descriptive matter, inwhich there is illustrated and described a preferred embodiment of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially broken away perspective view of a preferredembodiment of a tonneau cover apparatus 8 of the present application,including a flexible cover 10 in accordance with the present invention,attached to a pickup truck 6 (shown in broken lines) with the cover 10being disposed in a covered or fixed stretching position;

FIG. 2 is a fragmentary perpective view of the preferred tonneau coverapparatus 8 shown in FIG. 1 (but separated from the pickup truck),illustrating the end plate and flexible cover after they have beenrotated out of the covered or fixed stretching position shown in FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view which illustrates (1)the preferred apparatus in the fixed stretching position, shown in FIG.1, in which the end plate exerts a tensile force on the flexible cover,and (2) (in phantom lines) the preferred apparatus as it is unlatchedand rotated out of the fixed stretching position in which the flexiblecover is relatively loose or relaxed;

FIG. 4 is an enlarged simplified side view of a latch member 190 of thepreferred apparatus, when disengaged from the apparatus partial orcomplete views of the latch member, or parts thereof, shown in situ invarious;

FIG. 5 is a simplified fragmentary perspective view of a side rail 106of the preferred apparatus, partially shown in FIG. 3, with the latchmember attached;

FIG. 6 is an enlarged perspective view of the locking member 60 of thepreferred apparatus, which illustrates the position of the lockingfinger and the location of the frictional elements;

FIG. 7 is an enlarged fragmentary perspective view of the locking member60 as it is being inserted into a channel 38 in the end plate 20 andillustrates the interaction between the end plate channel 38 and thefrictional imparting element 74 and the guide strips 80 (not shown) and82;

FIG. 8 is an enlarged fragmentary sectional view as seen generally alongline 8—8 of FIG. 3 which shows a portion of the preferred apparatus asit is attached to an inner wall 14 of a side wall 12 of a cargo box of apickup truck and which illustrates in phantom lines the locking memberas it moves into engagement with the side rail 106;

FIG. 9 is an enlarged fragmentary sectional view of the latching memberillustrating the range of motion as the release member 196 is depressedfrom the position shown in phantom so that the end plate 20 (not shown)can be disengaged from the end plate engagement member 170 (not shown)and showing the adjustability of the latching member relative to theinwardly extending flange 118 of the side rail;

FIG. 10 is a fragmentary perspective view from inside a cargo box of thepickup truck when the tailgate is in an open position (not shown), theview showing the preferred apparatus in the fixed stretching positionwith the latching member operatively engaging the end plate, and thelocking member disengaged from the inwardly extending flange;

FIG. 11 is a fragmentary perspective view showing an alternateembodiment of the invention, which is similar to the preferredembodiment, but has different end plate 420 which engages in a somewhatdifferent way with the end plate engagement member 440, wherein the endplate 420 is shown in an engaged position, but not in a fixed stretchingposition similar to that shown in FIG. 3;

FIG. 12 is an enlarged fragmentary sectional view of the alternateembodiment of FIG. 11 which illustrates the alternate apparatus in afixed stretching position in which the end plate 420 exerts a tensileforce to a flexible cover 410, and which illustrates in phantom linesthe apparatus as it is unlatched and rotated out of the fixed stretchingposition in which the flexible cover is relatively relaxed;

FIG. 13 is an enlarged fragmentary sectional view of a flier alternateembodiment of the present tonneau cover apparatus, showing only a verysmall portion of an alternate pickup truck 506 in phantom, and showingthe end plate 520 in a fixed stretching position;

FIG. 14 is an enlarged fragmentary sectional view of the furtheralternate embodiment shown in FIG. 13, shown separate from the pickuptruck, but showing the end plate 520 pivoted out of the fixed stretchingposition such that the flexible cover 510 is relatively loose orrelaxed;

FIG. 15 is a fragmentary sectional view of the further embodiment shownin FIG. 13 as generally seen from line 15—15 of FIG. 13 showing the siderail 606 clamped to the sidewall 512 of the pickup truck 506 and showingthe locking member 560 in a locking position where the finger portion568 of the locking member 560 is engaged with an inwardly extendingflange 618 of the side rail 606 to hold the end plate 520 in the fixedstretching position;

FIG. 16 is a fragmentary section view similar to that shown in FIG. 8,but of a portion of yet another alternate embodiment which is the sameas the preferred embodiment shown in FIG. 8 except that there is nolatch member and the locking member 760, while it is similar to thelocking member 60 shown in FIG. 8, is shown in a disengaged positionwhere the locking member 760 is in contact with the inwardly extendingflange 818, furthermore, the locking member 760 does not have guidestrips or a friction imparting element as disclosed in association withlocking member 60 and locking member 760 slides easily within channel738 which is the same as channel 38 in end plate 20 of the preferredembodiment shown in FIG. 8; the locking member 760 differing fromlocking member 60 also because it is secured within the end plate 720with a tension spring 774 which biases the locking member 760 toward aposition consistent with a latched or locked position shown in FIG. 17;

FIG. 17 is a further fragmentary sectional view of the alternateembodiment shown in FIG. 16 except the locking member 760 is shown in alocked or latched position where the finger portion 768 is fully engagedwith the inwardly extending flange 818 and abuts against stop bolt 819which prevents locking member 760 from being drawn in further by thetension spring 774; and

FIG. 18 is a fragmentary sectional view similar to that shown in FIG.17, but of a further alternate embodiment the same as that shown in FIG.17 except that the locking member 960 is biased toward a positionconsistent with a locked or a latched position by a compression spring980 pushing the locking member 960 to such position rather thanoperating in the manner the tension spring 774 shown in FIG. 17, thatbiases the locking member 760 by pulling on it.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to the drawings, and specifically FIGS. 1-10, there isillustrated a preferred embodiment of the present invention, whereinreference numeral 6 designates a vehicle, preferably a pickup truck,reference numeral 8 designates a preferred tonneau cover apparatus andreference numeral 10 designates the flexible cover. FIG. 1 illustrates aflexible cover 10 in use on a cargo box 11 of a pickup truck 6 havingtwo outer sidewalls 121 each having an inner sidewall 14 (shown in FIG.8), a forward end 13 and a tailgate 16, preferably with a release handleand lock mechanism 18, actuated with a key (not shown) or,alternatively, a remotely actuated lock mechanism, having a remotekeyless actuator (not shown), like those which are now well known in theart. As depicted, the flexible cover 10 is covering a top of a perimeterof the cargo box 11 of the pickup truck 6. The flexible cover 10 issecured to a front plate 19 and an end plate 20 each of which aresecured to support frame 104 that includes rails 106 which are clampedto the respective sidewalls 12 of the pickup truck 6.

FIG. 2 shows the preferred tonneau cover apparatus 8, including theflexible, stretchable fabric cover 10, separated from the pickup truck.The rearward end of the flexible cover is attached to an elongated endplate 20 having an end plate cap 90 with an exterior surface 92. Theother end of the flexible cover 10 is preferably attached to the frontplate 19 (shown in FIG. 1) in a manner similar to that disclosed in U.S.Pat. No. 5,906,407 to Schmeichel ('407 patent), the disclosure of whichis hereby incorporated herein by reference. The front plate 19 ispreferably secured to the respective side rails 106 in an equivalent orsimilar manner that is disclosed in U.S. Pat. No. 5,076,338, thedisclosure of which is hereby incorporated by reference, or in otherSchmeichel patents that are incorporated herein by reference. Inpreferred embodiments, the front plate 19 will be secured to therespective side rails 106 in the manner disclosed in the '407 patent.The flexible cover 10 is preferably made of a resilient fabric material,which is preferably laminated to a polyester sheet to give it strength,flexibility, additional resilience, and water resistance.

The preferred tonneau cover apparatus 8 is secured to the sidewalls 12of the pickup truck 6 using clamps 130 (see FIGS. 3 and 8), which securethe respective side rails 106 to the inner wall 14, which is anextension of the sidewall 12. The front plate 19 is secured to therespective side rails 106 as described above and the end plate 20 isengaged to a pair of end plate engagement members 170 (see FIGS. 3 and5). When the end plate 20 is engaged it will initially occupy a positionwith respect to the respective engagement members 170 similar to thatshown in phantom in FIG. 3. The distal end 32 of the end plate 20 isthen pushed downward and the peak or crest 26 of the end plate 20 willthen pivot against the pivot point 176 of the respective engagementmember 170 such that the foot 30 of the end plate 20 will push the pawlelement 200 of the latch member 190 downward and out of its path, sothat the end plate 20 can become fully engaged within the respectiveengagement members 170 and the foot 30 becomes fully engaged within theinclined portion 178 (see FIG. 5) of the engagement member 170, as shownin FIG. 3, in this position, the end plate 20 is in a closed or a fixedstretching position, where the end plate 20 preferably exerts a tensileforce upon the flexible cover 10 so that the flexible cover 10 willstretch and remain taught over the cargo box 11.

When the end plate 20 is in the fixed stretching position, lockingmembers 60 can be pushed into a closed or locking position to preventthe end plate 20 from being disengaged from the respective engagementmembers 170. The locking members 60 slide, when pushed, within a secondchannel 38 in the end plate 20. Because locking members 60 are designedto create friction when moved within the second channel 38, it takessome force to move the locking members 60 into a locking position likethat shown in phantom in FIG. 8. This requirement for force to slide thelocking members is designed to prevent the locking members fromaccidentally sliding into such a position when they are meant to bedisengaged, and from sliding into an unlocked or disengaged positionsimilar to that shown in FIG. 8 when they are meant to be in the fullyengaged or locked position shown in phantom in FIG. 8.

When the end plate 20 is in the closed or fixed stretching positionshown in FIG. 3, and it is desirable to open the tonneau cover apparatus8 to gain access to the cargo box 11, the locking members 60 must bemoved to a position where they are not engaged with the inwardlyextending flange 118 of the support structure 104. The latch member 190must then be depressed to a position consistent with that shown inphantom in FIG. 3 so that the pawl element 200 is disengaged from thefoot 30 of the end plate 20 so that the foot can pivot out of the cavityproximate the inclined portion 178 of the engagement member 170 withoutbeing impeded by the pawl element 200. This can be accomplished eitherby pushing downward on the release member 196 or pulling downward on thegrip element 236 with enough force to bond the latch member 190. In thisway, the end plate 20 is freed to pivot out of the fully engagedrelationship with the respective engagement members 170 and release thetension on the flexible cover and even-roll the flexible cover up aroundthe end plate in a manner similar to that described in the previouslydescribed and incorporated Schmeichel patents.

As depicted in FIG. 2, the end plate 20 is disengaged from a pawlelement 200 on a latching member 190 and a locking member 60 isdisengaged from an inward extending flange 118 of a side rail 106 (shownin FIG. 8) prior to pivoting or rotating the end plate 20 about an endplate engagement member 170 and out of a fixed stretching position shownin FIG. 1. Although a generally rectangularly shaped end plate 20 isdepicted in the drawings, it is understood that the end plate 20 mayhave other configurations without departing from the spirit and scope ofthe invention. Moreover, it is understood that only selected portions ofthe end plate 20 are necessary to normal operation and that unnecessaryportions may be omitted, if desired. In preferred embodiments the endplate is made of an aluminum alloy material. Referring now also to FIG.7, the end plate 20 has an underside 56, a base portion 24, an uppersurface 33 and a trailing surface 34.

FIGS. 2, 3, 5 and 810 also illustrate attachment of the flexible cover10 to the support frame 104. As depicted, the support frame 104preferably includes side rails 106 having a vertical attachment portion108 including a sidewall contacting surface 110, an inwardly extendingportion 114, and an inclined portion 116 onto which one half of a twopart, hook and loop type fastener 124 has been attached. The flexiblecover 10 has been provided with the other half of the two part, hook andloop type fastener 124 to enable the sides of the flexible cover 10 tobe removably attached to the inclined portion 116 of the side rail 106.One method by which an end of the flexible cover 10 is attached to aportion of the end plate 20 shown in FIG. 2 is described in U.S. Pat.Nos. 5,076,338 and 5,174,353, the disclosures of which are incorporatedby reference. Note that in the embodiment shown in FIG. 2 the strap 86is attached to a locking member 60 rather than a portion of the endplate itself. It will be appreciated that this strap might be just aseffective if it were attached directly to the end plate (not shown) inother embodiments and that it need not be attached to the lockingmembers 60. As shown in FIG. 12, which discloses an alternateembodiment, the flexible cover material can be secured in such a waythat additional material creates a flap 123 which covers the top of thetailgate 16 and provides a further seal or covering to limit the passageof dust and moisture into the cargo box 11.

FIGS. 3 and 10 illustrate the apparatus as it pivots or rotates positioninto and out of a fixed stretching position and when in the fixedstretching position. As best seen in phantom lines, end plate 20includes a distal end 32, which terminates in a first channel 36, whichreceives an end of the flexible cover 10. The end plate 20 also includesa second channel 38, which is sized to slidingly receive a lockingmember 60. The second channel 38 is generally T-shaped and includesopposing sidewalls 40, 42 an upper wall 44 and opposing flanges 46, 48.The end plate or stretcher bar 20 also includes cavities 52, 54, whichare sized to receive plugs 94, 96 that extend from an end plate cap 90.The plugs 94, 96 are provided with ribs 98, 100 which allow the endplate cap 90 to be frictionally attached to the end plate 20. When theend plate 20 is rotated or pivoted into a fixed stretching position, apeak or crest 26 of the end plate 20 contacts a pivot point 176 of anend plate engagement member, or strike 170. A ridge 28 on the baseportion 24 of the end plate 20 then sweeps across an upper surface 177of an extension portion 174 of the end plate engagement member 170.Referring now also to FIGS. 4-5 and 8-9, the ridge 28 then contacts anddeflects the pawl element 200 of the engagement portion 194 of alatching member 190. That is to say, the latching member 190 isdeflected from a first position where the end plate is prevented frombeing disengaged from the fixed stretching position to a secondposition, which permits the apparatus to be disengaged from the fixedstretching position. After the ridge 28 passes the pawl element 200, twothings occur. First, the base portion 24 is moved into a base portionreceiving area 180 in the end plate engagement member 170, and second,the latching member 190 moves from the second position to the firstposition wherein the pawl element 200 of the latching member 190 isbiased into a pawl receiving area 50 of the end plate 20 where itconfronts the foot 30 on the end plate 20. The pawl element 200 may bedisengaged from the foot 30 and withdrawn from the pawl receiving area50 by placing downward pressure on the release member 196 or pullingdownward on the grip element 236, which is engaged with the latchingmember 190 through an opening 234.

Turning more specifically to FIG. 4, the latching member 190 has a bodyportion 192, an engagement portion 194, a release member 196 and anattachment portion 198. The engagement portion 194 includes a pawlelement 200 having a ridge engagement surface 202 and a foot engagementsurface 204. Adjacent the foot engagement surface 204 is a recess orrelief 208 which accommodates a fastening element 186 used to attach theend plate engagement member or strike 170 to the support frame 104 (seeFIG. 3). Note that the angle “A” between the foot engagement surface 204and a top surface 207 of the recess 206 of the body portion 192 is lessthan or equal to 90 degrees, preferably about 88 degrees to prevent theend plate 20 from being forced out of the fixed stretching position whenlifting force is applied upwardly upon the bottom of end plate 20 whenit is in the fixed stretching position as shown in FIG. 3. The uppersurface 212 of the latch member 190 is generally parallel with the topsurface 207 of the recess 206, so the angle “A” will be the same as anangle (not shown) between the foot engagement surface 204 and the uppersurface 212 of the latch member 190. The latching member 190 includes arelease member 196, which is preferably an upright member 208 with anenlarged head 210. In operation, the release member 196 is manipulatedby placing downward pressure on the enlarged head 210 of the releasemember 196 through the flexible cover 10 and is used to disengage thepawl element 200 from the foot 30 of the end plate 20. Referring nowalso to FIG. 9, an upwardly extending recess 214, having a throatportion 216, partially delineates or separates the attachment portion198 from the body portion 192. The attachment portion 198 is connectedto the body portion 192 by a thinned portion 218. The attachment portion198 includes a slot 226, which receives a fastener 220 and a threadedaperture 228, which receives an adjustment member or element 230. Theattachment portion 198 also includes a limiter or stop 232, whichcontrols the range of motion of the latching member 190 as it moves fromthe first position to the second position. Note that the upper and lowersurfaces 198 a, 198 b of the attachment portion 198, that are parallelto broken line 198 c (shown schematically in FIG. 4), reside at anangle, B, with respect to upper and lower surfaces 192 a, 192 b of thebody portion 192, respectively, when the latch member 190 is disengagedfrom the side rail 106. This angle “B” is about 1 to about 7, preferablyabout 4 degrees and ensures that the upper surface 212 of the latchingmember 190 biasingly contacts an inwardly extending flange 118 on a siderail 106 when the latching member 190 is attached thereto as shown inFIGS. 3 and 5. The latching member 190 is preferably manufactured from aglass filled nylon resin material.

FIG. 5 illustrates the juxtaposition between a side rail 106 an endplate engagement member or strike 170 and a latching member 190. As canbe seen, the side rail 106 includes an inclined portion 116 and aninwardly extending flange 118 with an upper surface 120. The end plateengagement member 170 generally includes a body portion 172 and anextension portion 174. More specifically, the body portion 172 includesa pivot point 176, an inclined portion 178 and an end plate base portionreceiving area 180. The extension portion 174 is somewhat tapered andincludes an upper surface 177 and an aperture 188. Referring now also toFIG. 3, the end plate engagement member 170 has a lower surface 184common to the body portion 172 and the extension portion 174. Alsoreferring to FIG. 3, the body portion 172 of the end plate engagementmember 170 includes an integrally attached fastening element 186, aportion of which extends beyond the body portion 172 and through anaperture 126 in the flange 118 and which is secured by an appropriatelysized nut 127. Like the aforementioned latching element 190, the endplate engagement member 170 is formed so that the lower surface 184 isslightly concave. This allows the extension portion 174 to biasinglycontact the upper surface 120 of the flange 118 when the end plateengagement member 170 is attached thereto. As with the aforementionedlatching member, the end plate engagement member 170 is preferablymanufactured from a glass filled nylon resin material. In a morepreferred embodiment, this distance will be about {fraction (13/16)}thsof an inch.

The bolt or fastening element 186 preferably has an axis “b” whichpasses through the center of the bolt 186. This axis “b” is preferablylocated a distance, “d₁, from the pivot point 176, denoted by line “a”in FIG. 3, which is ¾ths of an inch in the most preferred embodimentshown in FIG. 3. In alternative embodiments, however, this distance,“d₁”, will be equal to or less than 2.0 inches, more preferably 1.5inches, even more preferably 1.0 inch.

FIG. 6 illustrates a locking member 60 in isolation prior to use. Thelocking member 60 generally comprises an upper portion 62, a lowerportion 64 and a web 66 therebetween. In particular, the upper portion62 includes a top surface 72 onto which a friction imparting element 74has been affixed. The term friction-imparting element in the context ofthis invention is understood to mean a material, which is capable ofcausing friction between the locking member 60 and the end plate 20 whenthe locking member is moved within the end plate. The preferred frictionimparting element 74 in this instance is a loop portion of a hook andloop type fastening element. The upper portion 62 also includes opposingside surfaces 76, 78 and corresponding opposite guide strips 80, 82. Theterm guide strip in the context of this invention is understood to meana structure, which is preferably relatively rigid in comparison to thefriction-imparting element, although it need not be so. The preferredguide strip in this instance is composed of the same material as thelocking member. As illustrated, the upper portion 62 has the samegeneral cross-sectional T-shape as the channel 38 into which it isinserted. While a T-shape is illustrated, it is understood that thechannel 38 and upper portion 62 may be formed in other complimentaryconfigurations without departing from the spirit and scope of theinvention. When locking member 60 is first placed into the channel 38,the guide strips 80, 82 are generally shaved off a bit to fit thechannel. Once the resulting shavings 83 fall away, the locking member 60will be friction fit in the channel 38. This is important so that thelocking member will not inadvertently slide closed when it is intendedto be open or slide open when it is intended to be closed. Turning tothe lower portion 64, one end of the lower portion includes a finger 68,which extends beyond the body of the lower portion 64. The fingerportion 68 includes an engagement surface 70, which is configured toslidingly engage the flange 118 of a side rail 106 (see FIG. 8). Thelower portion 64 is also provided with a slot 84 through which a strap86 may be threaded, the strap 86 serving to position and align the baseportion 24 of the end plate 20 adjacent the end plate engagement memberor strike 170 prior to pivoting the end plate into the fixed stretchingposition shown in FIGS. 1 and 3.

FIG. 7 illustrates a locking member 60 as it is being installed into achannel 38 of an end plate 20. As the locking member 60 is inserted intothe channel 38, the friction-imparting element 74 is compressed andcomes into sliding contact with the upper surface 44 of the channel 38(see FIG. 3). At the same time, the guide strips 80, 82 are engaged bysidewalls 40, 42 of channel 38 (see also FIG. 3). The sidewalls 40, 42being constructed of relatively harder material, modify the oppositeguide strips as the locking member is inserted into the channel 38. Asdepicted a portion 83 of the opposite guide strips are planed away orshaved during assembly. Thus, the width of the upper portion 62 andattendant guide strips 80, 82 is then sized to friction fit within thewidth of the channel 38. In especially cold weather, the resin materialof the preferred locking member 60 and the aluminum alloy of thepreferred end plate both contract, but the locking member 60 willcontract somewhat more than the end plate 20. In especially hot weather,both the preferred locking member 60, made of resin material, and thepreferred end plate 20, made of aluminum alloy, will expand, but it isbelieved that the expansion of the aluminum alloy will be greater. Ineach case, therefore, in both especially cold temperatures and inespecially hot temperatures, the preferred locking member 60 and thepreferred end plate 20 will contract or expand at different rates andthis will cause some looseness of the sliding locking member 60 withinthe end plate 20. The use of the friction-imparting element 74 isintended to compensate for this variation and to prevent the lockingmember 60 from sliding into a locked position when it has been placed,and is intended to remain in, an open position.

In the preferred embodiment, the friction imparting element 74 and theguide strips 80, 82, are all in sliding contact with the walls 40, 42,44, respectively, while the remaining surfaces of the upper portion 606are in sliding contact with flanges 46, 48 of the second channel 38.These sliding contacts combine to provide a relatively constantresistive force over a wide range of temperatures as the locking elementis manipulated along the channel. While the preferred embodimentfeatures one friction imparting element and a plurality of guide stripselements, it is understood that other combinations may be used. As withthe aforementioned latching member and end plate engagement member, thelocking member 60 is preferably manufactured from a glass filled nylonresin material.

FIG. 8 illustrates a portion of the apparatus attached to an innersidewall 14 of the pickup truck. More specifically, a side rail 106 ofthe support frame is attached to the inner sidewall 14 preferably by aplurality of clamps 130. The clamp 130 has a first arm 132 and a secondarm 150. As illustrated, the first arm 132 and the second arm 150 engageeach other at contact surfaces 139 and 157, respectively. The contactsurfaces 139 and 157 serve several different functions. First, thecontact surfaces 139 and 157 provide a point about which the arms 132and 150 may pivot with respect to each other. And second, the contactsurfaces 139 and 157 serve to align and guide the arms 132 and 150 sothat they are brought into confronting relation with each other when theclamp 130 is tightened. The first arm 132 includes a proximal end 134, atransition portion 136 and a distal end 138. The proximal end 134includes the a contact surface 139 having a recess 140, which isconfigured to receive and rotatingly support a pivot or projection 158on the second arm 150. The preferred configuration of the recess 140 isgenerally oriented orthogonally to the longitudinal axis of the arm 132.The proximal end 134 also includes a transversely aligned cavity 144,which is coaxially aligned with an aperture 166 in a nut 167. The cavity144 is sized to securely retain the nut 167 of a fastening element 169,which includes nut 167 and bolt 164. The cavity 144 is sized to looselyreceive the shaft of a bolt 164 of the fastening element 169. Althoughthe aperture 166 is sized to fit the bolt 164, the cavity is much largerwhich allows the clamp to fall open easily at the end nearest the distalend 138 and distal non-parallel side joint between two surfaces similarto that shown in FIG. 8. The distal end 138 of the first arm 132includes a sidewall-contacting portion 146, which is preferably providedwith a grip element 148. The grip element 148 has an irregular shapedsurface and may be suitably affixed to the sidewall-contacting portion146. The preferred grip element 148 has an irregular surface similar tocourse sandpaper and the preferred method of affixing is by using anadhesive. The second arm 150 includes a proximal end 152, a transitionportion 154 and a distal end 156. As mentioned above, the proximal endincludes a contact surface 157 having a pivot or projection 158, whichis configured to be rotatingly supported within a recess 140 in theproximal end 134 of the first arm 132. As with the recess 140, thepreferred configuration of the projection is generally orientedorthogonally to the longitudinal axis of the arm 150. The proximal end152 of the second arm also includes a transversely aligned cavity 145,which is sized to loosely receive the shaft of a bolt 164 of thefastening element 169. The distal end 156 includes a siderail-contacting portion 162. As depicted, the side rail contactingportion 162 is configured to mesh with a similarly configured surface ona vertical attachment portion 108 of a side rail 106. Since theoversized cavities 144, 145 of the respective first and second arms 132,150 allow the respective arms to pivot within the joint created by theinsertion of the pivot 158 into the pivot receiving recess 140, therespective side rail and sidewall contact portions 146, 162,respectively, can pass through a range of non-parallel orientations withrespect to one another especially enabling the clamp 130 to forciblyhold together a pair of relatively flat objects whose opposite surfaceswhen joined together present non parallel surfaces.

In operation, to secure a side rail 108 to an inner wall 14 of a truck,a side rail 106 is brought into contact with an inner sidewall 14 of atruck 6. A clamp 130 is then positioned so that it straddles the innersidewall 14 and the side rail 106. With the recess 140 and theprojection 158 of the respective contact surfaces 139 and 157 incommunication with each other, the fastening element is then snugged upso that the distal ends 138 and 156 contact the sidewall 14 and siderail 106, respectively. The fastening element is then manipulated togradually increase the clamping force. As the force is increased severalthings occur. First, the arms 132 and 150 are aligned and guided by thecooperative interaction of the contact surfaces 139 and 157. Second,limiter surfaces 142 and 160 on the first and second arms 132, 150,respectively, converge towards each other, and third, the arms 132, 160flex slightly, at the transition portions 138, 154, respectively, wherethey have some give due to the materials used to make them and thedesign of respective first and second arms 132, 150 which include thenarrower transition portions 136, 154, respectively. When the limitersurfaces 142 and 160 contact each other, attachment of the side rail 106to an inner sidewall 14 is essentially completed. This is because thedamp may not be easily over tightened. With this preferred embodiment,not only is the possibility of overtightening substantially reduced, butthe clamp 130 provides a relatively constant damping force, whichcompensates for differences in thickness of the material to be clampedtogether and also differences in attachment points.

FIG. 8 also illustrates the operation of the locking member 60 as it maybe manipulated between a first position (shown in phantom lines) whereit operatively connects an end plate 20 to a side rail 106 of a supportframe 104 and a second position where the locking member 60 isdisengaged from the side rail 106 of the support frame 104. Note in thefirst position, that engagement surface 70 of the finger portion 68engages the lower surface 122 of the side rail flange 118.

FIG. 9 illustrates in broken line a position of the latching member 190at the point where either the release member 196 has been manipulated byplacing a downward force upon it, or by pulling downward on the bodyportion 192 or the chord 236 secured to the far end of body portion 192and the pawl element 200 (see FIG. 4) has been disengaged from the pawlelement receiving area 50 of the end plate 20 (see FIG. 3). That is, thelatching member 190 has been moved to the second position. Note that thethroat portion 216 has been effectively closed and the body portion 192is in contact with the limiter 232. As the release member 196 ismanipulated, it is contained within or encircled by an appropriatelyover-sized opening 128 in the inwardly extending flange 118 of a siderail 106. The latching member 190 is attached to the flange 118 by afastening element 219, such as a bolt 220 and attendant washer 222 andnut 224. The bolt 220 is inserted through an appropriately sizedaperture 126 and through the latching member 190, after which it issecured with a washer 222 and nut 224. The latching member 190 may beadjusted relative to the flange 118 and bolt 220 by the provision of asomewhat oversized slot 226, which slidingly admits the shaft of a bolt220 of the fastening element 219. Positioning of the shaft of the bolt220 within the slot 226 may be achieved by manipulating an adjustmentbolt 230, which is threadably received in a threaded aperture 228 withinthe attachment portion 198 of the latch member 190.

Referring now specifically to FIG. 10, an end plate 20 is shown in thefixed stretching position in which the pawl element 200 (see FIGS. 3 and5) of the latching member 190 projects through the flange 118 of a siderail 106 and into the pawl receiving area 50 of the end plate 20. Thelocking member 60 has been manipulated or moved to the second positionso that it lies inboard of the flange 118. In this position, the finger68 does not operatively connect the end plate 20 to the support frame.Note that the strap 86 has one end, which is attached to the lockingmember 60, and another end which is attached to a mid bar or bow 250.Such an arrangement serves to guide the peak/crest 26 of the end plate20 into operative contact with the pivot point 176 of the end plateengagement member 170 prior to rotating the end plate 20 into the fixedstretching position.

Referring now also to FIGS. 11 and 12, a further embodiment of thetonneau cover apparatus 408 is depicted. A flexible cover 410 is shownattached to an end plate 420 having a side panel 430. This embodimentdiffers from the preferred embodiment in that the an end plate 420 isprovided with generally radially shaped base portion 422 and the endplate engagement member 440 is provided with a reciprocally shaped baseportion receiving area 442 so that the base portion 422 can slidablypivot within the base portion receiving area 442 when fully engagedtherewith as shown in FIG. 11, such that the end plate 420 can be liftedaway from the fixed stretching position, shown in FIG. 12, and the baseportion 422 has pivoted within the receiving area 442, slightly awayfrom the fixed, stretching position. As shown in phantom in FIG. 12,when the base portion 422 is pivoted further, it will come away from thebase portion receiving area 442, but not before it has slidingly pivotedsomewhat within the receiving area 442.

In this embodiment, the reciprocating radial base portion 422 and baseportion receiving area 442 of the end plate engagement member 440compliment each other so that the base portion 422 can pivot smoothlywithin the engagement member 440 through a limited but significantradius. When the base portion 422 has pivoted far enough that the catchpoint 424 of the end plate 420 engagements the pivot point 444 of theengagement member 440, the notch or dip 426 between the catch point 424and the arcuate surface 428 of the base portion 422 will rotate or slideover the rounded surface 446 of the pivot point 444, enabling the baseportion 422 to disengage from the base portion receiving area 442 of theend plate engagement member 440.

Referring now also to FIGS. 13, 14, and 15, a further alternateembodiment of the present invention is disclosed. In this embodiment,the end plate 520 again has a radial base portion 522 that engages areciprocating radial base portion receiving area 542. The base portion522 can slide smoothly within the base portion receiving area 542 in amanner similar to that disclosed with respect to the embodimentdisclosed in FIGS. 11 and 12, but the arcuate catch point 424 and thearcuate surface 428, in the embodiment disclosed in FIGS. 11 and 12, arereplaced with a flat catch surface 524. This surface joins to a portionof the radial surface 525 to form a notch or dip 526 at the junctionthereof. In this case, however, when the notch or dip 526 becomesengaged with the preferably round surface of the pivot point 676 of theengagement member 670, the notch 526 will slide over or partially aroundthe pivot point 676, as the end plate 520 pivots further and the baseportion 522 disengages from the radial base portion receiving area 542.

The alternate embodiment shown in FIGS. 13, 14 and 15 also includes alocking member 560 that engages an inward extending flange 618 of a siderail 606 in a manner similar to that disclosed in the preferredembodiment, except that the locking member 560 is configured differentlyand the finger portion 568 is configured somewhat differently. Inaddition the locking member 560 is secured within a channel 538 bysecuring a bolt 539 to the locking member 560 with a nut 541. The bolt539 slides easily within the channel 538 to engage the inwardlyextending flange 618 of the side rail 606. In preferred embodiments, theend plate 520 will have a pair of radial base portions 522 proximate therespective ends of the end plate 520 which are configured toreciprocally engage a pair of engagement members 670 secured to each ofa pair of side rails 606 attached to respective sidewalls (not shown) ofthe pickup truck 506. The other features of this alternate inventionsare similar to or the equivalent to those features of the preferredembodiment disclosed in FIGS. 1-10. The further alternate embodiment ofthe invention includes a tonneau cover apparatus 508 having a supportframe 804, which can be secured to a side wall (not shown) of a pick-uptruck (not shown) using a clamp 630 secured at least in part with a bolt664. A flexible cover 510 is shown, which is secured to the end plate520 within a channel 536, shown in FIG. 13.

Referring now also to FIGS. 16 and 17, yet another alternate embodimentof the present invention is disclosed in which the alternate embodimentdiffers from the preferred embodiment disclosed in FIGS. 1-10, byproviding an alternate locking member 760 which slides easily within achannel 738 similar to the second channel 38 of the preferredembodiment. The alternate embodiment includes a support frame 804 and aside rail 806 like those associated with the previously disclosedembodiment shown in FIGS. 1-10. In the alternate embodiment shown inFIGS. 16 and 17, the locking member 760 does not include the frictionimparting elements or guide strips of the preferred embodiment. Instead,the alternate end plate 720 includes a tension spring 774 secured ateach end of the elongated and plate 720 to bias each of two lockingmembers toward a position consistent with a dosed or locked positionsimilar to that shown in FIG. 17. The tension springs 774 are secured tothe respective interior surfaces (not shown) of respective end caps 790at each of the ends 793 of the alternate end plate 720 and to therespective locking members 760, thereby biasing each of the lockingmembers 760 toward a pair of stop bolts 819 secured to the end plate 720proximate each of the respective ends 793 of the end plate 720. A drawcord or cable 765 is also attached to each of the respective lockingmembers. Each of the respective draw cods are preferably passed throughan eyebolt guide 767 and gathered together in a guide actuator 769.

During use, the alternate end plate 720 provides a locking or latchmechanism because the chamfered or beveled bottom surface 781 of each ofthe finger portions 768 of each locking member 760 will be displacedwhen the end plate 720 pivots with respect to the engagement members(not shown) into a closed or fixed stretching position from a positionin which the end plate 720 is engaged with the respective engagementmembers (not shown), but has not pivoted into the position shown in FIG.17. In FIG. 16, the locking members 760 are just beginning to bedisplaced as the end plate 720 pivots down to a closed position shown inFIG. 17. When the locking members 760 rest against the stop bolts 819,against which they are biased by the tension spring 774, they willengage the flange 818 if the end plate 720 is in the closed or fixedstretching position. As the end plate 720 is pivoted with respect to theengagement members (not shown), the beveled bottom surface 781 willfirst contact the upper side of the end 821 of the respective inwardlyextending flange 818, will be forced away from the stop bolt 819 untilthe finger portion 768 passes below the flange 818 and end plate 720 isfully engaged as shown in FIG. 17. In FIG. 17, the beveled bottomsurface 781 is no longer engaged with the upper side of the end 821 ofthe inwardly extending flange 818, and the spring biased locking memberwill engage the flange 818 as shown in FIG. 17. When the end plate 720is not engaged as shown in FIG. 17 the spring biased locking member 720will slide to the same position shown in FIG. 17, because it will springbiased against the stop bolt 819 which is positioned within the endplate 720 such that the locking member 760 will stop against the stopbolt 819 is the same position it will occupy within the end plate 720when the locking member 760 is biased up against the end 821 of theflange 818.

In order to lift the end plate 720 and pivot it out of the fixedstretching position in which it resides in FIG. 17, a user can draw thedraw cords or cables 765 by pulling on the pull actuator 769, therebydrawing the locking members 760 away from each of the respective flanges818, thereby disengaging the respective finger portions 768 from therespective flanges 818 as shown in phantom in FIG. 17 when the lockingmembers 760 are in this position, the end plate 720 can be pivoted outof the respective engagement members, and the cover 710 can be rolled upin order to gain better access to the cargo box.

Yet another alternate embodiment is shown in FIG. 18 where an embodimentlike that shown in FIGS. 16 and 17 is shown, but which differs primarilyonly because the tension springs 774 of the embodiment shown in FIGS. 16and 17 are replaced by compression springs 974 which push, rather thanpull the locking member 960 or members, if there are more than one,which there preferably are, against the flange 1018 and/or the stop bolt1019. In this case, the compression spring 974 slides over and isengaged by a first spring guide protrusion 977 extending away from thelocking member 960 and a second spring guide protrusion 979 extendingaway from a spring stop 983. All the other features of this embodimentare preferably the same as the features of the alternate embodimentshown in FIGS. 16 and 17 and this embodiment operates generally in thesame way with the exception of the operation of the compression spring974 as compared to the tension spring 774. The embodiment shown in FIG.18 includes a support frame 1004 having a side rail 1006. The end plate920 is shown in an engaged position. The flexible cover 910 is engagedwith the support frame 1004 and the finger 968 of the locking member960, configured to slidingly engage an outwardly extending flange 1018of the support frame 1004, is shown in an engage position, similar tothat shown in FIG. 17 with respect to the prior embodiment, wherein thefinger 968 can be slidingly positioned under an end 1021 of theoutwardly extending flange 1018, as shown.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present invention have been setfort in the foregoing description, together with details of thestructure and function of the invention, the disclosure is illustrativeonly, and changes may be made in detail, especially in matters of shape,size and arrangement of parts within the principles of the invention tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed.

1. A tonneau cover apparatus for removable attachment about a top of aperimeter of a cargo box of a pickup truck, the perimeter of the cargobox including a forward end, two opposing sidewalls and a tailgate, thetailgate being positioned rearward of the forward end, the tonneau coverapparatus comprising: a flexible cover, the flexible cover having firstand second ends; a support frame for attachment to the cargo box; thesupport frame having two opposing side rails and a pair of end plateengagement members, each of which is secured to one of the respectiveopposing side rails in a position rearward of the forward end when thetonneau cover apparatus is attached to the cargo box; an end plateattached to the second end of the flexible cover, the end plateconfigured to cooperatively engage the respective end plate engagementmembers when the flexible cover is drawn over the top of the perimeterof the cargo box; wherein the end plate engagement members cooperate toengage the end plate in a full engagement position when the first end ofthe flexible cover is operatively connected to the support frame forwardof the respective end plate engagement members, such that the end plateis in a closed position when the end plate is in the full engagementposition, wherein the flexible cover is stretched so as to place atension on the flexible cover; and a locking member, the locking memberbeing secured to the end plate and movable between a first position anda second position when the and plate is in the closed position; whereinthe locking member prevents the end plate from being disengaged from theclosed position when the locking member is in the first position inwhich an extension of the locking member engages the side rail adjacentto the end plate to prevent such movement, and wherein the end plate canbe disengaged from the closed position when the locking member is in thesecond position.
 2. The tonneau cover apparatus according to claim 1,wherein the end plate has an underside and the locking member isoperatively connected to the underside of the end plate.
 3. The tonneaucover apparatus according to claim 1, wherein the locking member isspring biased toward the fist position.
 4. The tonneau cover apparatusaccording to claim 1 wherein the tonneau cover apparatus includes anelongated member attached to the locking member such that force can beplaced upon the locking member by pulling the elongated member inopposition to a spring biasing force biasing the locking member towardthe first position by drawing the locking member away from the firstposition toward the second position.
 5. The tonneau cover apparatusaccording to claim 1, wherein the locking member is spring biased towardthe first position and the locking member is operatively connected to anunderside of the end plate and positioned in such a manner that thesupport frame displaces the locking member from the first position tothe second position for a brief period of time when the end plate pivotswith respect to the support frame into the fixed stretching position. 6.The tonneau cover apparatus according to claim 1, the locking memberbeing a first locking member and the tonneau cover apparatus furtherincludes a second locking member, each of the respective first andsecond locking members being secured to the end plate proximaterespective opposite ends of the end plate; wherein each of the opposingside rails include an inwardly extending flange portion and each lockingmember includes a finger portion, the finger portion of each lockingmember being engaged with the inwardly extending flange portion of therespective opposing side rail when the respective locking member is in afirst position, the finger portion of each of the respect lockingmembers disengaging from the inwardly extending flange portion of therespective side rail when the respective locking member is moved fromthe first position to a second position.
 7. The tonneau cover apparatusaccording to claim 6, wherein each of the respective first and secondlocking members is biased toward the first position and force isrequired to displace the respective first and second locking membersfrom the first position.
 8. The tonneau cover apparatus according toclaim 7, wherein the end plate includes a pair of springs, each springinterconnected between the end plate and one of the locking members soas to provide a biasing force between the end plate and the respectivelocking member such that each of the respective locking members arebiased toward the first position.
 9. The tonneau cover apparatusaccording to claim 8, wherein the tonneau cover apparatus includes firstand second elongated members attached to each of the respective lockingmembers such that force can be placed upon each respective lockingmember by pulling each of the respective elongated members in oppositionto a respective spring biasing force biasing each of the respectivelocking members toward the respective first positions by drawing each ofthe respective locking members away farm the respective fist positiontoward the respective second position.
 10. The tonneau cover apparatusaccording to claim 9, wherein the respective springs are selected fromthe group consisting of compression springs and tension springs.
 11. Thetonneau cover apparatus according to claim 10, wherein the spring is atension spring.
 12. The tonneau cover apparatus according to claim 10,wherein the spring is a compression spring.
 13. The tonneau coverapparatus according to claim 1, wherein the side rail includes aninwardly extending flange portion and the locking member includes anoutwardly extended finger portion, the finger portion of the lockingmember being engaged with the inwardly extending flange portion adjacentto the end plate and rearward of the respective first and secondengagement positions with respect to the forward end when the tonneaucover apparatus is attached to the cargo box and the locking member isin the first position, the finger portion of the locking memberdisengaging from the inwardly extending flange portion when the lockingmember is moved from the first position to the second position.
 14. Thetonneau cover apparatus according to claim 13, the locking member beinga first locking member and the tonneau cover apparatus further includinga second locking member that is a functional and structural mirror imageof the first locking member when operatively connected to the end plate,the second locking member being secured to on end of the end plate andthe first locking member being secured to the opposite end of the endplate.
 15. The tonneau cover apparatus according to claim 13, whereinthe end plate includes a spring, the spring being interconnected betweenthe end plate and the locking member so as to provide a biasing tensionbetween the end plate and the spring such that the locking member isbiased toward the first position.
 16. The tonneau cover apparatusaccording to claim 13, wherein the locking member has an upper portionhaving a main body which is slidably retained by the end plate, thefinger portion is spaced apart from the upper portion and extendsoutwardly beyond the main body of the upper portion, and the lockingmember is biased toward the first position and force is required todisplace the locking members from the first position.
 17. The tonneaucover apparatus according to claim 16, wherein the end plate includes aspring, the spring being interconnected between the end plate and thelocking member so as to provide a biasing tension between the end plateand the spring such that the locking member is biased toward the firstposition.
 18. The tonneau cover apparatus according to claim 17, whereinthe spring is selected from the group consisting of compression springsand tension springs.
 19. The tonneau cover apparatus according to claim18, wherein the spring is a tension spring.
 20. The tonneau coverapparatus according to claim 18, wherein the spring is a compressionspring.
 21. The tonneau cover apparatus according to claim 13, whereinthe locking member includes an upper portion having a main body which isslidably retained by the end plate, and the finger portion is spacedapart from the upper portion and extends outwardly beyond the main bodyof the upper portion.
 22. The tonneau cover apparatus according to claim21, wherein the end plate includes a generally “T” shaped channel and across-section of the upper portion of the locking member is generally“T” shaped, the generally “T” shaped channel of the end plate configuredto slidingly receive and retain the generally “T” shaped cross-sectionof the upper portion.
 23. The tonneau cover apparatus according to claim22, further including oppositely disposed guide strips positionedbetween interior surfaces of the generally T” shaped channel and anexterior surface of the generally “T” shaped upper portion of thelocking member, the respective guide strips each imparting a frictionalforce which resists motion between the generally “T” shaped upperposition of the locking member as it moves within the generally “T”shaped channel of the end plate.
 24. The tonneau cover apparatusaccording to claim 22, wherein the generally “T” shaped upper portion ofthe locking member includes a friction imparting element and twooppositely opposed guide strips, the friction imparting elementextending beyond the main body of the generally “T” shaped upper portionof the locking member to slidingly engage an interior surface of thegenerally “T” shaped channel, the friction imparting element and therespective guide strips creating frictional forces which resist motionby the locking member as the locking member moves relative to the endplate.
 25. The tonneau cover apparatus according to claim 22, furtherincluding a friction imparting element positioned between an interiorsurface of the generally “T” shaped channel and an exterior surface ofthe generally “T” shaped upper portion of the locking member to whichthe friction imparting element is attached, the friction impartingelement imparting a frictional force which resists motion by thegenerally “T” shaped upper portion of the locking member as it moveswithin the generally “T” shaped channel of the end pate.
 26. The tonneaucover apparatus according to claim 25, wherein the friction impartingelement is attached to an exterior surface of the generally “T” shapedupper portion of the locking member and the exterior surface of theupper element onto which the friction imparting element is attached is atop surface.
 27. The tonneau cover apparatus according to claim 26,wherein the friction imparting element comprises a strip of a loopportion of a hook and loop type strip fastener, the strip extendingalong the longitudinal extent of the upper member.
 28. A tonneau coverapparatus for removable attachment about a top of a perimeter of a cargobox of a pickup truck, the perimeter of the cargo box including aforward end, two opposing sidewalls and a tailgate, the tailgate beingpositioned rearward of the forward end, the tonneau cover apparatuscomprising: a flexible cover, the flexible cover having first and secondends; a support frame for attachment to the cargo box; the support framehaving two opposing side rails and a pair of end plate engagementmembers, each of which is secured to one of the respective opposing siderails in a position rearward of the forward end when the tonneau coverapparatus is attached to the cargo box; an end plate attached to thesecond end of the flexible cover, the end plate configured tocooperatively engage the respective end plate engagement members whenthe flexible cover is drawn over the top of the perimeter of the cargobox; wherein the end plate engagement members cooperate to engage theend plate in a full engagement position when the first end of theflexible cover is operatively connected to the support frame forward ofthe respective end plate engagement members, such that the end plate isin a dosed position when the end plate is in the full engagementposition, wherein the flexible cover is stretched so as to place atension on the flexible cover; and a locking member, the locking memberbeing slidably secured within a channel within the end plate and movablebetween a first position and a second position when the end plate is inthe dosed position; wherein the locking member prevents the end platefrom being disengaged from the dosed position when the locking member isin the first position in which an extension of the locking memberengages the side rail adjacent to the end plate to prevent suchmovement, and wherein the end plate can be disengaged from the closedposition when the locking member is in the second position.
 29. Thetonneau cover apparatus according to claim 28, wherein the end plate hasan underside and the locking member is operatively connected to theunderside of the end plate.
 30. The tonneau cover apparatus according toclaim 28, wherein the locking member is spring biased toward the firstposition.
 31. The tonneau cover apparatus according to claim 28, whereinthe tonneau cover apparatus includes an elongated member attached to thelocking member such that force can be placed upon the locking member bypulling the elongated member in opposition to a spring biasing forcebiasing the locking member toward the first position by drawing thelocking member away from the first position toward the second position.32. The tonneau cover apparatus according to claim 28, wherein thelocking member is spring biased toward the first position and thelocking member is operatively connected to en underside of the end plateand positioned in such a manner that the support frame displaces thelocking member from the first position to the second position for abrief period of time when the end plate pivots with respect to thesupport frame into the fixed stretching position.
 33. The tonneau coverapparatus according to claim 28, the locking member being a firstlocking member and the tonneau cover apparatus further includes a secondlocking member, each of the respective first and second locking membersbeing secured to the end plate proximate respective opposite ends of theend plate; wherein each of the opposing side rails include an inwardlyextending flange portion and each locking member includes a fingerportion, the finger portion of each locking member being engaged withthe inwardly extending flange portion of the respective opposing siderail when the respective locking member is in a first position, thefinger portion of each of the respective locking members disengagingfrom the inwardly extending flange portion of the respective side railwhen the respective locking member is moved from the first position to asecond position.
 34. The tonneau cover apparatus according to claim 33,wherein each of the respective first and second locking members isbiased toward the first position and force is required to displace therespective first and second locking members from the first position. 35.The tonneau cover apparatus according to claim 34, wherein the end plateincludes a pair of springs, each spring interconnected between the endplate and one of the locking members so as to provide a biasing forcebetween the end plate and the respective locking member such that eachof the respective locking members are biased toward the first position.36. The tonneau cover apparatus according to claim 35, wherein thetonneau cover apparatus includes first and second elongated membersattached to each of the respective locking members such that force canbe placed upon each respective locking member by pulling each of therespective elongated members in opposition to a respective springbiasing force biasing each of the respective locking members toward therespective first positions by drawing each of the respective lockingmembers away from the respective first position toward the respectivesecond position.
 37. The tonneau cover apparatus according to claim 36,wherein the respective springs are selected from the group consisting ofcompression springs and tension springs.
 38. The tonneau cover apparatusaccording to claim 37, wherein the spring is a tension spring.
 39. Thetonneau cover apparatus according to claim 37, wherein the spring is acompression spring.
 40. The tonneau cover apparatus according to claim28, wherein the side rail includes an inwardly extending flange portionand the locking member includes an outwardly extended finger portion,the finger portion of the locking member being engaged with the inwardlyextending flange portion adjacent to the end plate and rearward of therespective first and second engagement positions with respect to theforward end when the tonneau cover apparatus is attached to the cargobox and the locking member is in the first position, the finger portionof the locking member disengaging from the inwardly extending flangeportion when the locking member is moved from the first position to thesecond position.
 41. The tonneau cover apparatus according to claim 40,the locking member being a first locking member and the tonneau coverapparatus further including a second locking member that is a functionaland structural minor image of the first locking member when operativelyconnected to the end plate, the second locking member being secured toone end of the end plate and the first locking member being secured tothe opposite end of the end plate.
 42. The tonneau cover apparatusaccording to claim 40, wherein the end plate includes a spring, thespring being interconnected between the end plate and the locking memberso as to provide a biasing tension between the end plate and the springsuch that the locking member is biased toward the first position. 43.The tonneau cover apparatus according to claim 40, wherein the lockingmember has an upper portion having a main body which is slidablyretained by the end plate, the finger portion is spaced apart from theupper portion and extends outwardly beyond the main body of the upperportion, and the locking member is biased toward the first position andforce is required to displace the locking members from the firstposition.
 44. The tonneau cover apparatus according to claim 43, whereinthe end plate includes a spring, the spring being interconnected betweenthe end plate and the locking member so as to provide a biasing tensionbetween the end plate and the spring such that the locking member isbiased toward the first position.
 45. The tonneau cover apparatusaccording to claim 44, wherein the spring is selected from the groupconsisting of compression springs and tension springs.
 46. The tonneaucover apparatus according to claim 45, wherein the spring is a tensionspring.
 47. The tonneau cover apparatus according to claim 45, whereinthe spring is a compression spring.
 48. The tonneau cover apparatusaccording to claim 40, wherein the locking member includes an upperportion having a main body which is slidably retained by the end plate,and the finger portion is spaced apart from the upper portion andextends outwardly beyond the main body of the upper portion.
 49. Thetonneau cover apparatus according to claim 48, wherein the end plateincludes a generally “T” shaped channel and a cross-section of the upperportion of the locking member is generally “T” shaped, the generally “T”shaped channel of the end plate configured to slidingly receive andretain the generally “T” shaped cross-section of the upper portion. 50.The tonneau cover apparatus according to claim 49, further includingoppositely disposed guide strips positioned between interior surfaces ofthe generally “T” shaped channel and an exterior surface of thegenerally “T” shaped upper portion of the locking member, the respectiveguide strips each imparting a frictional force which resists motionbetween the generally “T” shaped upper position of the baking member asit moves within the generally “T” shaped channel of the end plate. 51.The tonneau cover apparatus according to claim 49, wherein the generally“T” shaped upper portion of the locking member includes a frictionimparting element and two oppositely opposed guide strips, the frictionimparting element extending beyond the main body of the generally “T”shaped upper portion of the locking member to slidingly engage aninterior surface of the generally “T” shaped channel, the frictionimparting element and the respective guide strips creating frictionalforces which resist motion by the locking member as the locking membermoves relative to the end plate.
 52. The tonneau cover apparatusaccording to claim 49, further including a friction imparting elementpositioned between an interior surface of the generally “T” shapedchannel and an exterior surface of the generally “T” shaped upperportion of the locking member to which the friction imparting element isattached, the friction imparting lament imparting a frictional forcewhich resists motion by the generally “T” shaped upper portion of thelocking member as it moves within the generally “T” shaped channel ofthe end plate.
 53. The tonneau cover apparatus according to claim 52,wherein the friction imparting element is attached to an exteriorsurface of the generally “T” shaped upper portion of the locking memberand the exterior surface of the upper element onto which the frictionimparting element is attached is a top surface.
 54. The tonneau coverapparatus according to claim 53, wherein the friction imparting elementcomprises a strip of a loop portion of a hook and loop type stripfastener, the strip extending along the longitudinal extent of the uppermember.